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Ground motion simulations in the Pollino region (Southern Italy) for
Mw 6.4 scenario events
ITIS023 Mercure Basin Fault ITCS038 Remediello-Mormanno Composite sourceDISS reports that the seismogenic potential associated to such faults is Mw 6.4.
Source Model – Mercure Basin Fault
Approximated 1D wave-propagation (ray theory)
Lenght=22km ; Width=13kmStrike, dip, rake= 335° , 60°, -90°Top depth = 1 km Mw=6.4
Slip distribution = Heterogeneous (with 2 main patches of slip)rupture velocity = 0.8 Vs
Spectral attenuation modelR=10km R=50km
Rovelli et al., 1988Cantore et al., 2011 – Irpinia 1<f<30 HzCastro et al., 2004 – Basilicata 2<f<10 Hz
GR=1/RVs= 3.4 km/sκ =0.035 s
DSMSynthetic seismograms are computed through a modified versione of the stochastic method proposed by Boore (1983) for point source model:
• Gaussian noise is modulated with acceleration envelopes, computed solving the rapresentation theorem for an extend source
• The amplitudes are scaled applying a Reference Fourier spectrum, whose parameters (corner frequency and distance from the fault ) are inferred from the modelling of the extend source.
=
X Random Noise
Deterministic Envelope
IFFT (point-source-like Reference Spectrum)
NS
Synthetic Seismogram
Ground motion maps (PGA bedrock)
scenario 1: northwestern rupture propagation
Ground motion maps (PGA bedrock)
scenario 2: bilateral rupture propagation
Ground motion maps (PGA bedrock)
scenario 3: southeastern rupture propagation
Ground motion maps (PGA bedrock)
GMPE scenario: ITA10 mean predictions
Comparioson with empirical GMPEs
Acc. Response Spectra at 2 sites
Mormanno
Lauria
Strong motion data from RAN and INGV stations
INGV stations